Antiviral compounds from traditional Chinese medicines Galla Chinese as inhibitors of HCV NS3 protease

Under the guidance of bioassay, the EtOAc extract fraction of the Traditional Chinese Medicine (TCM) Galla Chinese was found to be efficient in inhibiting the NS3 protease of HCV and purified the fraction to get three polyphenol compounds 1,2,6-tri-O-galloyl-β-D-glucose (1), 1,2,3,6-tetra-O-galloyl-β-D-glucose (2), and 1,2,3,4,6-penta-O-galloyl-β-D-glucose (3), which were identified as inhibitors of Hepatitis C Virus (HCV) NS3 protease. Compounds 1, 2, and 3 inhibited HCV NS3 protease with IC₅₀ of 1.89, 0.75, and 1.60 μM, respectively.